Sakhalin Island and Buccaneer Physicians

In re-reading Chekhov's "Sakhalin Island" late last night I ran across the following interesting passage:

"Иду в избу. Там в горнице сидит старик в красной рубахе, тяжело дышит и кашляет. Я даю ему доверов порошок - полегчало, но он в медицину не верит и говорит, что ему стало легче оттого, что он "отсиделся".

Сижу и думаю: остаться ночевать? Но ведь всю ночь будет кашлять этот дед, пожалуй, есть клопы, да и кто поручится, что завтра вода не разольется еще шире? Нет, уж лучше ехать!"

My translation:

"I went into the house. There was an old man in a red shirt sitting in the good room. He was breathing heavily and coughing. I gave him some доверов порошок (doverov poroshok, "dover powder"). It helped, but he didn't believe in medicine so he said that "sitting it out" was what had helped him.

"I sat there and considered whether or not I should spend the night. I knew the old man would be coughing all night, and I suspected there would be bed bugs. And who could say that the water wouldn't spread further tomorrow? No, I decided to keep going!"

As soon as I read доверов порошок I immediately thought that there must be a Mr. Dover somewhere. And there was:

Dover's Powder, a combination of opium and ipecac, was invented by Thomas Dover in 1732. His biography in the Oxford Dictionary of National Biography draws Dover as a colorful figure living in a colorful era. The man got his name in print for reasons ranging from his involvement in "privateering" (read "piracy") and the slave trade to his energetic promotion of his own remedies and his encouragement of patient self-diagnosis. The New York times ran an article about Dover on June 1, 1902 as a retrospective about an obscure figure who invented a remedy that was still very much in use at that time.

Chekhov took his trip to Sakhalin in 1890, and I found incomplete information in a Google Books preview of a 1933 dissertation that Dover's Powder was known in Russia as early as 1812.

The attraction of Dover's Powder at the time of its creation was that the inclusion of a small amount of ipecac (which causes vomiting) would supposedly prevent patients from overdosing.

It would be interesting to know if Chekhov, physician-writer-activist, knew anything about Thomas Dover, physician-pirate-activist.